JP5296578B2 - Automatic specimen tilting device for electron microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic sample inclination device for an electron microscope capable of automatically adjusting a sample inclination angle. <P>SOLUTION: The transmission electron microscope has at least: a control device for controlling movements of a sample movement mechanism 7 and a sample inclination mechanism 8; an imaging electron optical system 6 for imaging transmitted electrons transmitted from a sample 3 by using a multistage electron lens and a deflector; an image acquisition means 9 for an image-signalling imaged image; a memory means 11 for memorizing an image signal; and a computer 10 for analyzing the image signal memorized in the memory means 11 by reading out the image signal. The computer 10 memorizes the memory means 11 by acquiring an electron diffraction figure acquired in a current crystal orientation of the sample with a plurality of different sample inclination angles, and calculates an electron diffraction spot coordinate for each acquired electron diffraction figure, and calculates the center and a radius of an approximation circle by making circle approximation of an electron diffraction spot on the basis of the electron diffraction spot coordinate. Then, the sample inclination angle for minimizing the radius of the circle is set up to be the most suitable inclination angle. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an automatic sample tilting device for an electron microscope, and more particularly, to a transmission electron microscope that irradiates a sample with an electron beam and obtains an image obtained by enlarging and forming a transmission electron transmitted through the sample by an imaging electron optical system, The present invention relates to an automatic sample tilting apparatus for an electron microscope that automatically adjusts a sample tilt angle in order to match a crystal orientation of a crystalline sample with an electron beam incident direction.

  A transmission electron microscope (TEM) can perform high-resolution observation by irradiating a sample with an electron beam and enlarging an image of transmission electrons that have passed through the sample with an imaging electron optical system. In the case of a crystalline sample, the arrangement of molecules and atoms of the material can be examined by an electron diffraction pattern. Furthermore, there are many applied technologies such as elemental analysis by detecting X-rays emitted from a sample. Recently, an opportunity to use a scanning transmission electron image mode by scanning an electron beam on a sample and detecting the transmission electrons in synchronization with a scanning signal is increasing.

  By the way, when observing an electron diffraction pattern or the like with a transmission electron microscope, it is necessary to adjust the direction of the incident electron beam with respect to the crystal of the sample. Further, in recent years, there are cases where the electron beam incident orientation is aligned with a silicon crystal before fine dimension measurement of a semiconductor sample or the like is performed. This is because a slight deviation between the tilt angle of the sample and the incident direction of the electron beam may cause a measurement error.

  This sample and electron beam incident orientation alignment is performed by inclining the sample by a mechanically independent tilting mechanism in two axial directions perpendicular to each other. The adjustment of the sample tilt angle is normally performed manually while the operator changes the tilt angle and observes the change in the electron diffraction pattern.

  This type of device is a device that mathematically calculates the current crystal orientation from an electron diffraction pattern acquired at an arbitrary sample tilt angle, and mathematically calculates the tilt angle required to shift to the crystal orientation for the purpose of observation. Is known (see, for example, Patent Document 1).

  Also, in a transmission electron microscope sample holder having a biaxial sample rotation mechanism, the relationship between the initial crystal orientation of the sample observation position and the reference orientation is obtained from the rotating machine mechanism of the rotation mechanism, and from the orientation relationship to the target orientation A technique is known in which the rotation angle is calculated, the two-axis rotation mechanism is operated simultaneously by the rotation angle component according to a command from the computer, and the sample is tilted (see, for example, Patent Document 2).

JP-A-11-288679 (paragraphs 0013 to 0028, FIG. 1) JP-A-6-103948 (paragraphs 0018 to 0020, FIG. 1)

  At present, the adjustment of the sample inclination angle for adjusting the crystal orientation of the sample is mostly adjusted by an operator's manual operation. This operation can be adjusted in a few seconds for an experienced operator, but an unfamiliar operator has a great deal of time for adjustment. In the electron diffraction mode of the electron microscope, a very strong electron beam (spot) is incident on the fluorescent screen or the image acquisition device. Therefore, it is desirable to make adjustment in a short time in order to prevent the fluorescent screen from being burned in or the image acquisition device from being damaged.

  With the method disclosed in Patent Document 1, sufficient adjustment accuracy cannot be obtained unless the sample is sufficiently thin. For example, since most of the semiconductor samples are microfabricated samples using an FIB (focused ion beam apparatus) as the observation sample, the film thickness of the sample is often 100 nm or more depending on the skill of the operator. In some cases, sufficient adjustment accuracy cannot be obtained.

  In addition, data such as lattice constants of various materials necessary for calculation must be registered in a computer in advance. Therefore, the sample tilt angle cannot be automatically adjusted for materials not registered in the computer, and there is no versatility. Furthermore, the operator has to instruct the computer about the type of material and the crystal orientation every time, and there is a problem that the operability is poor.

  The present invention has been made in view of such problems, and an object thereof is to provide an automatic sample tilting device for an electron microscope capable of automatically adjusting the sample tilt angle for aligning the crystal orientation of the sample. Yes.

(1) The invention described in claim 1 is an irradiation electron optical system that irradiates a sample with an electron beam, a sample moving mechanism that moves the sample in the X direction, the Y direction, and the Z direction, and the sample is tilted by two orthogonal axes A possible sample tilting mechanism, a control device for controlling the operations of the sample moving mechanism and the sample tilting mechanism, and an imaging electron optical system that forms an image of transmitted electrons that have passed through the sample using a multistage electron lens and a deflector A transmission electron microscope having at least image acquisition means for converting the image formed into an image signal, storage means for storing the image signal, and a computer for reading and analyzing the image signal stored in the storage means; The computer acquires electron diffraction patterns obtained with the current crystal orientation of the sample at different sample tilt angles for each sample tilt axis, stores them in the storage means, and stores electron diffraction spot positions for each acquired electron diffraction pattern. It calculates, on the basis of electron diffraction spot position, by an electron diffraction spots circle approximation, to calculate the center and radius of the approximate circle is calculated by fitting the specimen rotation angle the radius of the circle is a minimum, the sample The tilt angle is set to the optimum sample tilt angle, and the control device moves the sample to the optimum sample tilt angle using the sample tilt mechanism.

(2) The invention described in claim 2 uses a method of calculating an optimum specimen tilt angle different from that of claim 1, characterized in that the computer has center coordinates of approximate circles calculated for each electron diffraction pattern. Is approximated by a linear function, the intersection point on the linear function line that makes the shortest distance between the linear function line and the direct spot center coordinate is calculated, and the sample inclination angle that can take this intersection point is calculated mathematically. , and the specimen rotation angle and the optimum sample tilt angle, the control device causes the movement of the sample to the optimum sample tilt angle using the specimen rotation mechanism, Ru near that.

  (3) In the invention according to claim 3, when acquiring a plurality of different electron diffraction patterns while changing the sample tilt angle, the observation field position before the sample tilt and the observation field position after the sample tilt are minute due to the sample tilt. In order to correct the position change, observation field position correction data or correction calculation formula for the sample tilt angle change is prepared for each sample tilt axis in advance, and the field position correction amount is corrected simultaneously with the sample tilt angle change using the sample moving mechanism. It is characterized by doing.

(1) According to the invention described in claim 1, for each sample tilt axis, an electron diffraction pattern obtained with the current crystal orientation of the sample at a plurality of different sample tilt angles is acquired, stored in the storage means, and acquired. Calculate the electron diffraction spot coordinates for each electron diffraction pattern, calculate the center and radius of the approximate circle by approximating the electron diffraction spot to a circle based on the electron diffraction spot coordinates, and the sample tilt angle that minimizes the radius of the circle Is set to the optimum sample tilt angle, the sample tilt angle for adjusting the crystal orientation of the sample can be automatically adjusted.

(2) According to the invention described in claim 2, the locus of the center coordinates of the approximate circle calculated for each electron diffraction pattern is approximated by a linear function, and the linear function straight line and the direct spot center coordinates are the shortest distance 1 Calculating the intersection point on the linear function line, mathematically calculating the sample tilt angle that can take this intersection point, and setting the sample tilt angle as the optimum sample tilt angle, the sample tilt angle for aligning the crystal orientation of the sample Can be adjusted automatically.

  (3) According to the invention described in claim 3, observation field position correction data or a correction calculation formula for the change in the sample tilt angle is prepared in advance for each sample tilt axis, and the field position correction amount is set simultaneously with the change in the sample tilt angle. By correcting using the moving mechanism, it is possible to automatically adjust the sample inclination angle for aligning the crystal orientation of the sample.

It is a block diagram which shows one Example of this invention. It is a figure which shows an electron diffraction pattern. It is explanatory drawing of circular approximation of acquisition of an electron diffraction pattern and the acquired electron diffraction pattern. It is explanatory drawing of labeling. It is explanatory drawing of temporary determination of a direct spot. It is a figure which shows the state of a circle approximation. It is explanatory drawing which calculates the optimal inclination angle from the locus | trajectory of the center of circular approximation. It is explanatory drawing that there exists the optimal position of the other inclination axis in a filling area | region.

Hereinafter, embodiments of the present invention will be described in detail.
Example 1
FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a transmission electron microscope (TEM). Reference numeral 2 denotes an electron gun provided in the TEM 1 for emitting electrons. Examples of the electron gun 2 include a thermionic emission type and a field emission type. 3 is a sample, and 4 is a sample stage on which the sample 3 is placed. 5 is an irradiation electron optical system for irradiating the sample 3 with the electron beam emitted from the electron gun 2 formed on the upper part of the sample 3, and 6 is transmitted through the sample 3 formed on the lower part of the sample 3. This is an imaging electron optical system that forms an electron beam using a multistage electron lens and a deflector.

  7 is a sample moving mechanism for moving the sample stage 4 in the XYZ directions, and 8 is a sample tilting mechanism capable of tilting the sample stage 4 with two axes orthogonal to each other. Reference numeral 9 denotes an image acquisition device such as a CCD camera provided under the TEM 1. A computer 10 controls the overall operation of the TEM 1. In the computer 10, 11 is an image signal memory for storing the image signal acquired by the image acquisition device 9 as digital data, and 12 is an image display mechanism for displaying the contents of the image signal memory 11. For example, a liquid crystal display is used as the image display mechanism 12.

  Reference numeral 13 denotes an analysis unit that reads out image signal data stored in the image signal memory 11 and performs predetermined analysis / calculation. Reference numeral 14 denotes an output of the analysis unit 13 that receives the output of the sample moving mechanism 7 and the sample tilting mechanism 8. It is a sample position correcting device for controlling the operation. The system configured as described above calculates a tilt direction and a tilt angle of the sample tilt mechanism necessary for moving to the target crystal orientation by detecting a plurality of electron diffraction patterns at different sample tilt angles. Hereinafter, the present invention will be described in detail.

  When the crystalline sample is irradiated with an electron beam in the electron diffraction mode, for example, an electron diffraction pattern as shown in FIG. 2 can be obtained. This electron diffraction pattern reflects the crystal orientation of the sample. (A) is a diffraction pattern in which the sample tilt angle is corrected, and (b) is a diffraction pattern in which the sample tilt angle is not corrected. Usually, immediately after the sample is inserted into the sample chamber of the electron microscope, for example, an electron diffraction pattern as shown in (b) is obtained. In the case of FIG. 2, the target crystal orientation is Si [110], and the crystal orientation is adjusted by adjusting the biaxial sample tilt mechanism 8 so as to obtain an electron diffraction pattern as shown in FIG. (A) of the figure is a figure whose tilt angle is corrected, and electron diffraction spots are regularly arranged. (B) is a figure in which the tilt angle is not corrected, and the electron diffraction spots are irregularly arranged.

  In order to automatically perform the above-described sample tilt, as shown in FIG. 3A, a plurality of electron diffraction patterns are acquired by the image acquisition device 9 while changing one of the two-axis sample tilt mechanisms 8, and a computer 10 image signal memories 11 are stored. Each electron diffraction pattern stored in the image signal memory 11 is read out and binarized on the computer 10 to separate the electron diffraction spot and the background. When binarization is performed, a place where a diffraction spot is present is binarized to white, and other areas are binarized to black.

The electron diffraction spot obtained by binarization is subjected to image processing such as labeling and luminance center of gravity calculation by the analysis unit 13 to calculate the center coordinates of each electron diffraction spot. FIG. 4 is an explanatory diagram of labeling. (A) is a binarized image before labeling. When this image is labeled, an image as shown in (b) is obtained. When labeling is detected, the computer 10 calculates the luminance centroid of each detected spot. In equations (1) and (2), the luminance centroid x coordinate is Gx and the luminance centroid y coordinate is Gy. If the gradation other than the target spot is set to 0 gradation and the image is f _ij , the luminance centroid can be calculated by the expressions (1) and (2).

  Next, as shown in (b), the analysis unit 13 performs circle approximation from the electron diffraction spot center coordinates for each diffraction pattern, and calculates the center and radius of the circle. Here, the circular approximation can be performed using a general mathematical method, for example, a least square method.

  Next, when the radius of the obtained approximate circle is plotted by the sample tilt angle of the biaxial sample tilt mechanism 8 when the electron diffraction pattern is acquired, it becomes as shown in (c). In the figure, the horizontal axis represents the inclination angle, and the vertical axis represents the radius (r) represented by the number of pixels. As for the radius of the approximate circle, the sample inclination angle is minimum at the optimum position, that is, the target crystal orientation position. In the figure, it can be seen that the radius r is minimum at an inclination angle of −1.8 °.

  When the optimum tilt angle is obtained, the sample position correcting unit 14 sets the tilt angle calculated by the biaxial sample tilt mechanism 8. The radius of the approximate circle is minimum at the sample tilt angle at the optimum position, that is, the target crystal orientation position. Therefore, the plot is fitted with a polynomial or the like, and the sample tilt angle of the biaxial sample tilt mechanism 8 that minimizes the radius of the approximate circle is calculated. The computer 10 sets the biaxial sample tilt mechanism 8 so that the calculated sample tilt angle is obtained. Next, with respect to the other axis of the biaxial sample tilting mechanism 8, the optimum sample tilt angle of the biaxial sample tilting mechanism 8 is calculated and set using the same method as described above.

As described above, according to Example 1, for each sample tilt axis, an electron diffraction pattern obtained with the current crystal orientation of the sample at different sample tilt angles is acquired, stored in the storage means, and acquired. Calculate the electron diffraction spot coordinates for each electron diffraction pattern, calculate the center and radius of the approximate circle by approximating the electron diffraction spot to a circle based on the electron diffraction spot coordinates, and the sample tilt angle that minimizes the radius of the circle By setting the optimum tilt angle, the sample tilt angle for adjusting the crystal orientation of the sample can be automatically adjusted.
(Example 2)
As shown in FIG. 1, the irradiation electron optical system 5 for irradiating the sample 3 with the electron beam emitted from the electron gun 2 and the sample 3 in the X direction (left and right direction), Y direction (up and down direction), Z direction ( A sample moving mechanism 7 for moving the sample in the height direction), a sample tilting mechanism 8 capable of tilting the sample by two orthogonal axes, and a control device (computer 10) for controlling the operations of the sample moving mechanism 7 and the sample tilting mechanism 8 , An imaging electron optical system 6 that forms an image of an electron beam transmitted through the sample 3 using a multistage electron lens and a polarizer, and an image obtained by converting the formed image into an image signal using an image acquisition device 9 such as a CCD camera, In a transmission electron microscope having at least a means for storing it in the memory 11 of the computer 10 and a computer for analyzing the image signal, it moves to the target crystal orientation by analyzing a plurality of electron diffraction patterns at different sample inclination angles. And it calculates the inclination direction and inclination angle of the specimen rotation mechanism 8 necessary in order.

  A specific operation will be described below. When the crystalline sample is irradiated with an electron beam in the electron diffraction mode, for example, an electron diffraction pattern as shown in FIG. 2 can be obtained. This electron diffraction pattern reflects the current crystal orientation of the sample. FIG. 2A shows the sample tilt angle corrected, and FIG. 2B shows the sample tilt angle uncorrected. Usually, immediately after the sample is inserted into the sample chamber of the electron microscope, for example, an electron diffraction pattern as shown in (b) is obtained. In the case of FIG. 2, the target crystal orientation is Si [110], and the crystal orientation is adjusted by adjusting the biaxial sample tilt mechanism 8 so as to obtain an electron diffraction pattern as shown in FIG.

  In order to automatically perform the above-described sample tilting, a plurality of electron diffraction patterns are acquired by the image acquisition device 9 while changing one of the two-axis sample tilting mechanisms 8 as shown in FIG. Is stored in the image signal memory 11. Each electron diffraction pattern stored in the image signal memory 11 of the computer 10 is read out and binarized on the computer 10 to separate the electron diffraction spot and the background. Next, the analysis unit 13 performs image processing such as labeling and luminance center of gravity calculation on the electron diffraction spot obtained by binarization, and calculates the center coordinates of each electron diffraction spot. Since labeling is as described in the first embodiment, detailed description thereof is omitted.

  The direct spot can be determined to be the spot of the maximum pixel, but the method is not limited here. FIG. 5 is an explanatory diagram of temporary determination of the direct spot. As shown in the figure, a large spot and a small spot appear in the diffraction pattern. In this case, a large spot can be temporarily determined as a direct spot.

  Next, as shown in FIG. 6, the computer 10 performs circle approximation from the center coordinates of the electron diffraction spot for each diffraction pattern, and calculates the center and radius of the circle. The circle approximation may be a general mathematical method, for example, a least square method.

  Here, it can be considered that the locus of the center of the approximate circle due to the change in the sample tilt angle has a substantially linear relationship. FIG. 6 is a diagram showing a circular approximation state. The optimum value of the sample tilt angle is when the distance between the locus of the center of the approximate circle and the direct spot is the shortest.

  FIG. 7 is an explanatory diagram for calculating the optimum tilt angle from the locus of the center of the circular approximation. F in (a) is a straight line obtained in FIG. ● on this straight line f is the center of the circular approximation. K is a direct spot. A point where a straight line passing through the direct spot K and f intersect at right angles as shown in FIG. The sample inclination angle at point A is calculated mathematically. Since the inclination angle of the point ● of the primary straight line f in FIG. 7 is known in advance, the corresponding inclination angle of the point A can be obtained by an interpolation method. When the optimum sample tilt angle is obtained, the computer 10 sets the biaxial sample tilt mechanism so that the calculated sample tilt angle is obtained.

In the case of FIG. 7, the optimum tilt angle of the other sample tilt axis is in the filled region in FIG. Therefore, the search direction of the optimum tilt angle of the other sample tilt axis 8 is determined. That is, with respect to the other axis of the biaxial sample tilting mechanism 8, the optimal sample tilt angle of the biaxial sample tilting mechanism 8 is calculated using the same method as described above. When acquiring a plurality of electron diffraction patterns, What is necessary is just to change a sample inclination angle so that the locus | trajectory of the center of an approximate circle may change to the arrow direction of FIG. This limits the search area for the sample tilt angle.
(Example 3)
Example 3 will be described with reference to FIG. In Example 1 and Example 2, a plurality of electron diffraction patterns are acquired while changing the sample tilt angle by the biaxial sample tilt mechanism. However, since the center of the sample tilt axis does not coincide with the observation field of the sample, the observation field of the sample moves when the sample tilt angle is changed.

  For this reason, it is conceivable that, depending on the sample inclination, the amorphous material portion may be irradiated with an electron beam or a crystalline material having a different proximity may be irradiated with an electron beam due to the sample inclination. Therefore, the computer 10 has correction data in advance as the amount of movement of the observation field of the sample due to the sample tilt and two-dimensional information for each sample tilt axis, and calculates a correction value by interpolation calculation from the correction data every time the tilt angle is changed, The sample is moved by using the sample moving mechanism 7 in FIG. 1 so as to cancel the moving amount of the observation field of the sample. A correction calculation formula may be used instead of the correction data.

  According to the third embodiment, observation field position correction data or a correction calculation formula for the change in the sample tilt angle is prepared in advance for each sample tilt axis, and the field position correction amount is corrected simultaneously with the sample tilt angle change using the sample moving mechanism. By doing so, the sample inclination angle for adjusting the crystal orientation of the sample can be automatically adjusted.

The effects of the present invention described above are listed as follows.
1) Even if the sample is difficult to obtain a clean electron diffraction spot, such as a relatively thick sample, the electron diffraction spot can be extracted by binarizing the electron diffraction pattern and the center coordinates of the diffraction spot can be calculated. The optimum sample tilt angle can be calculated with high accuracy.
2) Since the analysis method of the electron diffraction pattern is simple, the analysis time is very short, and the optimum sample tilt angle can be calculated at high speed. For this reason, it is possible to reduce accidents such as damage to the image acquisition device due to a strong electron diffraction spot and burn-in of the fluorescent screen.
3) There is no need to specify the type and orientation of the crystalline sample in advance, and the operator only has to press the button of the automatic sample tilt mechanism, and the operation can be performed even without knowledge of electron diffraction. In addition, it is not necessary to register the crystal orientation related information of the sample in the computer, so that not only the system can be made slim, but also various crystalline materials can be handled.
4) In the method of Example 2, when calculating the optimum sample tilt angle of the first sample tilt axis, the direction in which the optimum sample tilt angle of the other sample tilt axis exists is known, so the sample tilt angle search direction is It is limited, and the optimum sample inclination angle can be calculated with higher accuracy and in a shorter time.
5) The amount of movement of the electron beam irradiation position due to the sample tilt is prepared in advance as correction data or a correction calculation formula, thereby correcting the sample position for each sample tilt and minimizing the deviation in the observation field of the sample. Can be fastened. In addition, by preparing correction data in advance, it is not necessary to evaluate the amount of movement of the observation field deviation of the sample with an actual image for each sample inclination angle, and it is possible to realize high-speed processing.

1 Transmission microscope (TEM)
2 Electron gun 3 Sample 4 Sample stage 5 Irradiation electron optical system 6 Imaging electron optical system 7 Sample moving mechanism 8 Sample tilting mechanism 9 Image acquisition device 10 Computer 11 Image signal memory 12 Image display mechanism 13 Analyzing unit 14 Sample position correcting unit

Claims (3)

An irradiation electron optical system for irradiating the sample with an electron beam;
A sample moving mechanism for moving the sample in the X, Y, and Z directions;
A sample tilting mechanism capable of tilting the sample in two orthogonal axes;
A control device for controlling the operation of the sample moving mechanism and the sample tilting mechanism;
An imaging electron optical system that forms an image of transmitted electrons that have passed through the sample using a multistage electron lens and a deflector;
Image acquisition means for converting the formed image into an image signal;
Storage means for storing the image signal;
A computer that reads and analyzes the image signal stored in the storage means;
In a transmission electron microscope having at least
The computer
For each sample tilt axis, obtain an electron diffraction pattern obtained in the current crystal orientation of the sample at a plurality of different sample tilt angles and store it in the storage means,
Calculate the electron diffraction spot coordinates for each acquired electron diffraction pattern,
Based on the electron diffraction spot coordinates, calculate the center and radius of the approximate circle by approximating the electron diffraction spot to a circle.
Calculate the sample inclination angle that minimizes the radius of the circle by fitting,
The sample inclination angle is the optimum sample inclination angle,
The controller is
The sample using the specimen rotation mechanism is moved to the optimum sample tilt angle,
An automatic sample tilting device for an electron microscope. An irradiation electron optical system for irradiating the sample with an electron beam;
A sample moving mechanism for moving the sample in the X, Y, and Z directions;
A sample tilting mechanism capable of tilting the sample in two orthogonal axes;
A control device for controlling the operation of the sample moving mechanism and the sample tilting mechanism;
An imaging electron optical system that forms an image of transmitted electrons that have passed through the sample using a multistage electron lens and a deflector;
Image acquisition means for converting the formed image into an image signal;
Storage means for storing the image signal;
A computer that reads and analyzes the image signal stored in the storage means;
In a transmission electron microscope having at least
The computer
Approximate the locus of the center coordinates of the approximate circle calculated for each electron diffraction pattern with a linear function,
Calculate the intersection point on the linear function line that makes the shortest distance between the linear function line and the direct spot center coordinates,
Mathematically calculate the sample tilt angle that can take this intersection,
The sample inclination angle is the optimum sample inclination angle,
The control device includes :
Moving the sample to the optimum sample tilt angle using the sample tilt mechanism ;
Automatic specimen rotation apparatus that electron microscope to, characterized in that. When acquiring different electron diffraction patterns while changing the sample tilt angle,
In order to correct the minute position change between the observation field position before the sample tilt and the observation field position after the sample tilt due to the sample tilt, observation field position correction data or correction calculation formula for the sample tilt angle change is prepared in advance for each sample tilt axis. ,
The automatic sample tilting device for an electron microscope according to claim 1 or 2, wherein the visual field position correction amount is corrected using the sample moving mechanism simultaneously with the change in the sample tilt angle.